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  Government report on greenhouse gas emissions
  India is the third biggest greenhouse gas emitter with its contribution standing at 5.3 per cent behind countries like China and the USA, the Government said in Lok Sabha on August 22, 2011. "As per current information available, the countries which are the largest contributor, in percentage term regarding greenhouse gas emissions are China 19.5 per cent, USA 19.2 per cent, India 5.3 per cent, Russia 5.1 per cent, Japan 3.6 per cent and Germany 2.6 per cent,"
Environment Minister Jayanthi Natarajan said.
  India's greenhouse gas emissions grew 58 per cent between 1994 and 2007, official figures released on May 11, 2010 showed, underlining the country's growing importance in the fight against climate change. Emissions rose to 1.9 billion tonnes in 2007 versus 1.2 billion in 1994, with the industrial and transport sectors upping their share in Asia's third largest economy and confirming India's ranking among the world's top five carbon polluters. By way of comparison, between 1994 and 2007, India added more than the entire emissions produced annually by Australia.
  Figures in the government report, released by Environment Minister Jairam Ramesh at a conference in New Delhi, show India is closing in on Russia, now the world's third largest greenhouse gas emitter, at nearly 2.2 billion tonnes in 2007. India has also set a carbon intensity reduction target of 20 to 25 per cent by 2020 from 2005 levels. 

 
New studies on greenhouse pollutants
  According to a series of six papers appearing on November. 25, 2009 in the British journal The Lancet, cutting greenhouse pollutants could directly save millions of lives worldwide Analyses show global health benefits from cutting ozone and black carbon. Tackling climate change by reducing carbon dioxide and other greenhouse emissions will have major direct health benefits in addition to reducing the risk of climate change, especially in low-income countries.
  Two University of California, Berkeley, authors of the papers - Kirk R. Smith, professor of global environmental health, and Michael Jerrett, associate professor of environmental health sciences - will discuss the results at EST press conference in Washington, D.C.
  The studies, three of them coauthored by Smith and one coauthored by Jerrett, use case studies to demonstrate the co-benefits of tackling climate change in four sectors: electricity generation, household energy use, transportation, and food and agriculture.  Climate change due to emission of greenhouse gases from fossil fuel energy sources causes air pollution by increasing ground-level ozone and concentrations of fine particulate matter. The studies were commissioned by the NIEHS, part of the National Institutes of Health (NIH), in part to help inform discussions next month at the U.N. Framework Convention on Climate Change in Copenhagen. The NIEHS is one of the key sponsors of the international event.

 
U.N. gathering for global climate treaty
 
U.N. gathering on September 23, 2009 and the G-20 summit in Pittsburgh was an attempt to pressure rich nations to commit to a global climate treaty at Copenhagen, Denmark, in December, and to pay for poorer nations to burn less coal and preserve their forests.With a mere 76 days to go before the pivotal conference, it appeared an interim agreement might be the most that could be expected in December, leaving difficult details for later talks.
  "We are on the path to failure if we continue to act as we have," French President Nicolas Sarkozy cautioned. Much attention was fixed on Obama's first U.N. speech, in which he pledged the United States is "determined to act."  "The threat from climate change is serious, it is urgent, and it is growing,"  Obama said, after receiving loud applause. "And the time we have to reverse this tide is running out."
 
Greenhouse Gases
  Many chemical compounds found in the Earths atmosphere act as greenhouse gases. These gases allow sunlight to enter the atmosphere freely. When sunlight strikes the Earths surface, some of it is reflected back towards space as infrared radiation (heat). Greenhouse gases absorb this infrared radiation and trap the heat in the atmosphere. Over time, the amount of energy sent from the sun to the Earths surface should be about the same as the amount of energy radiated back into space, leaving the temperature of the Earths surface roughly constant. Many gases exhibit these greenhouse properties. Some of them occur in nature (water vapor, carbon dioxide, methane, and nitrous oxide), while others are exclusively human-made (like gases used for aerosols).
 Greenhouse gases naturally blanket the Earth and keep it about 33 degrees Celsius warmer than it would be without these gases in the atmosphere. This is called the Greenhouse Effect. Over the past century, the Earth has increased in temperature by about .5 degrees Celsius and many scientists believe this is because of an increase in concentration of the main greenhouse gases: carbon dioxide, methane, nitrous oxide, and fluorocarbons. People are now calling this climate change over the past century the beginning of Global Warming. Fears are that if people keep producing such gases at increasing rates, the results will be negative in nature, such as more severe floods and droughts, increasing prevalence of insects, sea levels rising, and Earth's precipitation may be redistributed. These changes to the environment will most likely cause negative effects on society, such as lower health and decreasing economic development. However, some scientists argue that the global warming we are experiencing now is a natural phenomenon, and is part of Earth's natural cycle. Presently, nobody can prove if either theory is correct, but one thing is certain; the world has been emitting greenhouse gases at extremely high rates and has shown only small signs of reducing emissions until the last few years. After the 1997 Kyoto Protocol, the world has finally taken the first step in reducing emissions. 

   The Greenhouse Effect
 
The "greenhouse effect" is the heating of the Earth due to the presence of greenhouse gases. It is named this way because of a similar effect produced by the glass panes of a greenhouse. Shorter-wavelength solar radiation from the sun passes through Earth's atmosphere, then is absorbed by the surface of the Earth, causing it to warm. Part of the absorbed energy is then reradiated back to the atmosphere as long wave infrared radiation. Little of this long wave radiation escapes back into space; the radiation cannot pass through the greenhouse gases in the atmosphere. The greenhouse gases selectively transmit the infrared waves, trapping some and allowing some to pass through into space. The greenhouse gases absorb these waves and reemits the waves downward, causing the lower atmosphere to warm.
 
Greenhouse Gases
 
The main greenhouse gases are: 
 Carbon Dioxide, 
 Methane, 
 Nitrous Oxide, 
 Fluorocarbons
 Atmospheric Levels of greenhouse gases is Increasing 
Levels of several important greenhouse gases have increased by about 25 percent since large-scale industrialization began around 150 years ago  During the past 20 years, about three-quarters of human-made carbon dioxide emissions were from burning fossil fuels. Trends in Atmospheric Concentrations and Anthropogenic Emissions of Carbon Dioxide
Concentrations of carbon dioxide in the atmosphere are naturally regulated by numerous processes collectively known as the carbon cycle.
The movement of carbon between the atmosphere and the land and oceans is dominated by natural processes, such as plant photosynthesis. While these natural processes can absorb some of the net 6.1 billion metric tons of anthropogenic carbon dioxide emissions produced each year (measured in carbon equivalent terms), an estimated 3.2 billion metric tons is added to the atmosphere annually. The Earths positive imbalance between emissions and absorption results in the continuing growth in greenhouse gases in the atmosphere.

The Effect of Greenhouse Gases have on Climate Change
 
Naturally, if there are more greenhouse gases in the atmosphere, this greenhouse effect will be more significant and raise the temperature of Earth more than if humans didn't emit as much greenhouse gases. Given the natural variability of the Earths climate, it is difficult to determine the extent of change that humans cause. In computer-based models, rising concentrations of greenhouse gases generally produce an increase in the average temperature of the Earth. Rising temperatures may, in turn, produce changes in weather, sea levels, and land use patterns, commonly referred to as climate change.
Assessments generally suggest that the Earth's climate has warmed over the past century and that human activity affecting the atmosphere is likely an important driving factor. A National Research Council study dated May 2001 stated, Greenhouse gases are accumulating in Earths atmosphere as a result of human activities, causing surface air temperatures and sub-surface ocean temperatures to rise. Temperatures are, in fact, rising. The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes is also a reflection of natural variability.
However, there is uncertainty in how the climate system varies naturally and reacts to emissions of greenhouse gases. Making progress in reducing uncertainties in projections of future climate will require better awareness and understanding of the buildup of greenhouse gases in the atmosphere and the behavior of the climate system. 
The Sources of Greenhouse Gases In the U.S., our greenhouse gas emissions come mostly from energy use. These are driven largely by economic growth, fuel used for electricity  generation, and weather patterns affecting heating and cooling needs. Energy-related carbon dioxide emissions, resulting from petroleum and natural gas, represent 82 percent of total U.S. human-made greenhouse gas emissions. The connection between energy use and carbon dioxide emissions is explored in the box on the reverse side . 
Another greenhouse gas, methane, comes from landfills, coal mines, oil and gas operations, and agriculture; it represents 9 percent of total emissions. Nitrous oxide (5 percent of total emissions), meanwhile, is emitted from burning fossil fuels and through the use of certain fertilizers and industrial processes. Human-made gases (2 percent of total emissions) are released as byproducts of industrial processes and through leakage.

   Effects of Global Warming on Society
 
Agriculturally, Dr. Sylvan H. Wittwer believes that global warming is good for the human race, because it helps increase food production. "The most determinant factor in agriculture production is climate. History reveals that for food production, warming is better than cooling." Dr. Wittwer says that carbon dioxide is an essential nutrient for the production of food, and food is one of the most important things in our lives. As the temperature rises, more farmland will be open towards the poles and the length of the growing season will also lengthen. With all the people who go hungry each day, Dr. Wittwer believes food production should be one of our main concerns. Dr. Wittwer is the scientific pioneer who conducted the original studies on atmospheric CO2 enhancement of the production of food crops. Increasing amounts of greenhouse gases in the atmosphere and global warming could also lead to more health concerns. A statement released from the Intergovernmental Panel on Climate Change (IPCC) said, "Climate change is likely to have wide-ranging and mostly adverse impacts on human health, with significant loss of life." As temperatures increase towards the poles, similar to farmland, insects and other pests migrate towards Earth's poles. These insects and pests could be allowed to migrate up to 550 Km or 550 miles. Some insects carry diseases such as malaria and dengue fever. Thus, an increase in these particular insects and pests closer to the poles results in an increase in these diseases. This could lead to 50 to 80 million additional cases of Malaria annually, a 10-15% increase. "Malaria and dengue fever are already beginning to spread pole wards", said Jane Lubchenco, past president of American Association for the advancement of science. 
 
  Cities and Climate Change
   Speaking on the theme "Cities and Climate Change" Brinda Sastry said, "While cities occupy only two per cent of the surface area, they are responsible for 75 per cent of energy consumption and 80 per cent of greenhouse gas emissions." To combat this, the cities need to be planned in a sustainable and green way, which can be done by sharing knowledge between government, city planners, civil societies and scientific communities.
 
The Prospect for Future Emissions 
  World carbon dioxide emissions are expected to increase by 1.9 percent annually between 2001 and 2025 Much of the increase in these emissions is expected to occur in the developing world where emerging economies, such as China and India, fuel economic development with fossil energy. Developing countries  emissions are expected to grow above the world average at 2.7 percent annually between 2001 and 2025; and surpass emissions of industrialized countries near 2018. 
   The U.S. produces about 25 percent of global carbon dioxide emissions from burning fossil fuels; primarily because our economy is the largest in the world and we meet 85 percent of our energy needs through burning fossil fuels. The U.S. is projected to lower its carbon intensity by 25 percent from 2001 to 2025, and remain below the world average.  

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